AUV observations of mixing in the tidal outflow from a Scottish sea loch

摘要: Freshwater outflows from estuarine systems carry nutrients, sediments, larvae and other materials into the coastal ocean where they mix ambient water. Loch Etive is one such estuary on west coast of Scotland that fed by a large rainfall catchment area, which outflow strongly modulated tidal basis. leaves loch ebbing tide in pulse released as thin layer, leading edge develops an undular bore or train internal solitary waves with strong mixing associated entrainment. A Hydroid 600 m depth-rated AUV equipped forward-mounted microstructure sensing package has been used conjunction moored measurements to study dynamics freshwater layers are regularly ocean. During observations conducted winter 2009 spring 2010 we observed turbulent bores Ardmucknish Bay, near entrance Etive. The passage depression were downward vertical movement near-surface water was enhanced above background over 2 orders magnitude.